The present invention provides a method for preparing barium hydroxide, in particular its octahydrate, from barium sulfide and sodium hydroxide.
Barium hydroxide octahydrate, Ba(OH).sub.2, 8H.sub.2 O, has numerous industrial applications, especially in the field of lubricants.
Several methods of making this barium hydroxide are known, but they all have disadvantages. Thus, for example, barium sulfide can be carefully oxidized by air or oxygen but this method is encumbered by the simultaneous formation of barium sulfite.
Barium hydroxide octahydrate can be prepared on a laboratory scale by hydrolysis of tribarium silicate but that method is not practical on an industrial scale.
Barium hydroxide octahydrate is obtainable industrially by the reaction of sodium hydroxide with barium chloride dihydrate, but this method also is fraught with disadvantages. The barium chloride itself must first be prepared from barium sulfide and furthermore the octahydrate crystals finally obtained tend to occlude chloride which is difficult to eliminate by washing. In addition, the sodium chloride by-product of this process has low economic value.